Sulfate

In chemistry, a sulfate (sulphate traditionally used in UK English but changed as per IUPAC guidelines) is a salt or ester of sulfuric acid. The sulfate ion is a group of atoms with the formula SO2−4. It consists of a central sulfur atom surrounded by four (equivalent) oxygen atoms. It occurs when sulfuric acid loses two hydrogens.

Structure of the sulfate ion

Hydrogen sulfate

Structure of hydrogen sulfate ion

Hydrogen sulfate, also known as bisulfate, is a conjugate base of sulfuric acid and conjugate acid of sulfate. The chemical formula is HSO₄^-. It is formed as part of sulfuric acid, H₂SO₄.

Chemical compounds containing this ion are known as bisulfates or hydrogen sulfates. An example would be sodium bisulfate. Hydrogen sulfates are acidic. They can be used as a weaker form of acid than sulfuric acid. It is a salt of sulfuric acid. In these compounds, sulfuric acid is deprotonated once.